But after a couple of serious scares, he’s now fighting back to health in a “halfway house” in Newcastle, having been allowed to leave the RVI’s Bubble Unit.

And if he keeps progressing well, hopes are high he’ll be able to spend his first birthday, October 15, back on Teesside - even if he won’t be able to mix with other children.

With his immunity levels still very low, Danny will only be allowed back for the day - and will have to stay away from other kids - before he’s whisked back up to Newcastle to continue his recovery.

And as he’ll be the only child at his own birthday party, it’s likely to be a quiet affair.

But he can make up for it in the future, as he’ll have two “birthdays” to celebrate.

Mum Claire explained: “They say August 10 is his new birthday now. That’s when he had his operation so that’s when his immune system was born again.”

And the fact he’s in this position at all amazes Claire. Watching Claire and her mum Julie McLaren play with Danny in the modest Newcastle semi they currently call home, it’s hard to believe the ordeal they’ve all been through.

Yet without a transplant, he probably wouldn’t have lived to see his teens.

And it hasn’t been plain sailing since his operation.

A bout of septicaemia, and an infected central line, left Danny seriously ill and back in intensive care, but his fighting spirt and zest for life saw him through.

Claire, 26, said: “With the septicaemia, I think they played it down to me but it was very serious. We could have lost him.

“Apparently he was playing with the play nurse one moment, then he just flopped.

“The nurses said he’d have to go to theatre because it was very serious and he’d need his central line out.”

Thankfully Danny - dubbed “little smiler” by nurses - pulled through.

And while he’ll be under a consultant for the rest of his life, the future looks so much brighter for a lively, playful tot who owes his life to someone his family know little about.

Claire said: “All we know about the donor is that he or she is an adult living in Germany.

“But if both parties are willing, after a year we can get in touch. I’d certainly like to - I can’t thank him or her enough.

“It’s been scary but it’s been worth it. When we found out he needed a transplant, we got told they might not even find a donor match in time, yet it’s all been done in a few months. We’re so grateful.

“Now we just want to get him back home and get back to some form of normality.”

For more about joining the bone marrow donor register, visit www.anthnoynolan.org